Staying hydrated, whilst exercising – yes, or no?

For many years, fitness enthusiasts, athletes and the like, have been told that dehydration (resulting in a heat stroke), is dangerous.  In 1996, the American College of Sports Medicine, suggested athletes drink before, during and after exercising, as a way to try to replace some of the water lost due to sweating.  However, this theory is completely flawed.

Firstly, the idea that any level of dehydration impairs the body’s ability to regulate its temperature, comes from a lab.  Here athletes exercised indoors, without any wind, in hot and humid conditions.  Without drinking water, it is only natural for the body temperature to rise.   The University of Cape Town did a similar study, but they not only simulated wind, but also increased the speed.  By doing so, it was found that the athletes’ body temperatures were constant, irrespective of the amount of water they drank.  Therefore, if the movement of air is sufficient, it doesn’t matter how much water an athlete drinks whilst exercising.

Second dilemma with the 1996-study, is that it is impossible to calculate how much sweat is lost during exercising.  Advising clients to drink plenty of fluids, can lead to the excessive intake of fluids.  Drinking too much can cause nausea and other discomforts; especially whilst exercising.

Thirdly; numerous research studies conducted during competitions, indicated that, if athletes drink according to their thirst, they lose between 2% and 5% of their body weight during exercises.  Although athletes might replace less fluid than what they lose when sweating, it still doesn’t cause serious problems.  There is one thing, though, that can happen:  hyponatremia.

Hyponatremia refers to the reduction in blood sodium levels, which occur due to a combination of factors:  genetic factors, the body’s regulation of the salt and water-balance, and excessive fluid intake.  When an athlete consumes too much fluid (in excess of sweat loss), then the athlete will gain weight during exercise.  This can cause a reduction in blood sodium levels and have lethal consequences. Moral of the story is:  listen to your body – always!  When your mouth is dry, you know it is time to drink water.  Cheers everyone, keep moving and stay hydrated!